Hydrogenation of 1, 4-butynediol to 1, 4-butanediol



United States Patent lice 2,953,605 e r I v p HYDROGENATION OF 1,4-BUTYNEDIOL T 1,4-BUTANEDIOL Eugene V. Hort, Westfield, 'N.'.l.,'"assignor to"( ;en eral I Aniline & Film Corporation,"New York, N.Y., a cor-, poration of Delaware 'fi jf, i; No Drawing. Filed Dec. 23, 1957, Ser. v

This invention relates to'the 'catalytic' hydrogenation of 1,4-butynediol, hereinafter referred toasbutynediolj to I I 1,4-butanediol, hereinafter referred to as'butanediol The hydrogenationof butynediol to butanegiiol"in he presence of a number of different catalysts jand by' a: number of difierent proceduresisknown;However, such previously proposed processe slhavebeen deficient roar centrated solutions are preferred, an aqueous solution hav-( ing a concentration of at least about 20%, and prefer ably 35 to 40% having been found highly advantageous and convenient. 'Such solutionss are available commercially at a pH of about 2.5 to 6. If desired, undiluted liquid butynediol may be used.

The nickel catalyst employed in the process of this inventionis preferably maintained in the liquid butynediolreaction medium in finely divided form. A Raneytype nickel catalyst (such catalysts are described in U.S.

Patent No. -1,638,190) is preferred as yielding optimum results. This type of catalyst is readily prepared by treat-.

ing an aluminum-nickel alloy with caustic soda to dissolve out the aluminum and leave the nickel in a highly divided and particularly effective form. The amount of nickel catalyst employed will generally range from about 0.:l to 10%, and preferably from about 0.5 to 3% by weight'ofthe butynediol,-*but such amount is not critical since-the catalyst.- is not deactivated during the hydrogenation: and may be reused. For a given amount of butynediol'to'behydrogenated, the rate of hydrogenation will vary directly with the amount of catalyst employed. ln 'accordance' with the instant process, the desired improved-results and advantages are obtained when the butynediol-nickel catalyst system also contains dispersed thereon about 3 to'l5% of copper by weight of the nickel catalyst, preferably as deposited from a soluble or dispersible-copper-compound. When an aqueous solution ofzb'utynediol isemployed, a water soluble copper compoundis'preferablyaddedthereto, particularly the copper salts of strong acids such as copper sulfate, copper chlowhich may be carried out "at relatively low temperatures and pressures. Another objectjof this invention isthe provision of a process for thehydrogenation ofibutynediol to butanediol in the presenceof a nickel catalyst at relatively low temperatures and pressures without substantial detriment to the yields ofthe-desired'product stantial amounts of undesirable by-products which would reduce the quality and yield of product desired. Other objects and advantages will appear as the description proceeds.

The attainment of the above objects is made possible by the instant inventive process for the catalytic hydrogenation of butynediol to butanediol comprising treating a solution of butynediol with hydrogen at a temperature of about 15 to 100 C. and a pressure of about 0 to 40 atmospheres gauge in the presence of a nickel catalyst carrying about 3 to 15% of copper by weight of the nickel catalyst. It has been found that the concurrent use of copper in the above defined process has little or no efli'ect on the activity of the nickel catalyst for hydrogenation but acts to suppress isomerization during the process which would tend to produce by-products having a detrimental effect upon the quality and yield of the desired butanediol. Further, the use of copper in this process enables the attainment of large savings in cost of operation and equipment because of the relatively low pressures which may be employed. The catalyst maintains its activity much longer, possibly because of the lowering of the formation of by-products, including gamma-hydroxybutyraldehyde, tetrahydrofurane, dihydrofurane, propionaldehyde, and the like, and the poisoning produced thereby, and may accordingly be reused repeatedly.

In carrying out the process of this invention, the butynediol is maintained in liquid condition at a pH of no more than about 7, preferably in solution in an inert solvent such as ethyl alcohol or other alcohols, dioxane, pr the like, but preferably in an aqueous solution. Conride; andncopper nitrate, and the copper salts of weak acids such .as copper cyanide, copper formate, copper acetate and copper carbonate. Copper oxide may also be usedLxSomeLof these'compounds are also solublein or- V ganic=solvents The .particular coppercompound employed-Lwill;ofcoursebe dependent upon the liquid reacand/ or without the simultaneous production of-any-sub-"'- tion-me.dium.=.r Thenickel replaces the copper from the solutioiiand: any residual soluble copper is reduced during 1 the hydrogenation. The precipitated copper is dispersed:

or coated on the nickel catalyst.

The hydrogenation of the butynediol in the reaction medium is carried out by maintaining an atmosphere of hydrogen over the surface of the reaction medium, contact therewith being facilitated by agitation as by rocking or shaking the reaction vessel, or by stirring the reaction medium with a high speed propeller or the like. Within the defined temperature range, use of a lower temperature yields a product of higher quality, but the reaction rate is lower. The optimum temperature range is about 40 to 60 C. At higher temperatures, reduction is incomplete and considerable butenediol is produced, as disclosed and claimed in my copending application Serial No. 704,240 filed on even date herewith, unless pressures of more than 4 atmospheres gauge are employed. Apparently, at temperatures of over 60 C. under the conditions of the hydrogenation, some substance present in the reaction medium acts to prevent complete reduction to the butanediol stage unless the pressure is increased as above noted. Such substance does not, however, poison the catalyst which may be reused repeatedly. Completion of the desired hydrogenation is indicated when absorption of hydrogen ceases, contact with the hydrogen bieng preferably continued for a further period to insure completion of this reaction.

The examples in the following table in which parts are by weight unless otherwise indicated are illustrative of the instant invention and are not to be regarded as limitative. In each of the examples, a rocking autoclave containing 3.0 moles of technical 35% aqueous butynediol and 6.0 g. (solids) of Raney-type nickel in the form of a 50% aqueous paste is held at 40 C. while Patented Sept. 20, 1960 maintaining therein the indicated hydrogen pressure in pounds'per square inch gauge (p.s.i.g.)' for three hours after the indicated time when hydrogen absorption ceased. In. each. case, the product. is. filtered. from. the. catalyst,

fractionall'y distilled, and the yield of the desired butanediol', and its properties, determined. In Examples 2,. 4.

and 6,. 2.0 g. of copper acetate is added to the. solution prior to hydrogenation.

In the above table, the refractive index of each product is given in the right-hand column, and the solidification point in the column adjacent thereto. Pure butane diol has a solidification point of about 20.9 C.. and. a

refractive index of about 1.4446. The results shown in: the table indicate that Examples 2, 4 and 6 carried out.

in the presence of copper in accordance with the instant invention, enable the attainment of improved yields: of

purer product as compared with comparative Examples 1, 3 and in which no copper was used.

This invention has been disclosed with respect. tocertain preferred embodiments, and there will become ohvious to persons skilled in. the art various modifications,-

equivalents or variations thereof which. are intended; to be included within the spirit and scope of this invention.

Iclaim: l. A process for the catalytic hydrogenation of 1,4- butynediol to 1,4-butanedio1 comprising treating. l,4--

butynediol in liquid. form with hydrogen at a pH of? no more than about 7, a temperature of about: 15 to 100 C- and a pressure of about 0 to 40 atmospheres gauge-inthe.

presence of a nickel catalyst carrying. about 3 to 15% of' copper by weight of the nickel catalyst, the pressure being.

more than 4 atmospheres gauge at temperatures of 6.0 to

2. A process as defined in claim 1 wherein the nickel catalyst" is a'Raney-type nickel catalyst.

3. A process as defined in claim 1 wherein the copper is derived from copper acetate.

4. A process for the catalytic hydrogenation of 1,4- butynediol to 1,4-butanediol comprising treating an aqueous solution of 1,4-butynediol' with hydrogen at a pH of no moreth-an about 7,.atemperatureof about 15to 100.

C. and a pressure of about 0 to 40' atmospheres gauge in the presence of. a. nickel catalyst carrying about 3 to 15% of copper by weight of the nickel catalyst, the pressure being more than 4 atmospheres gauge at. temperatures of so to 100 c.

5. A process as defined in claim 4 wherein the nickel catalyst is a Raney-type nickel catalyst.

6. A process for the catalytic hydrogenation of 1,4- butynediol to 1,4-butanediol comprising treating a solution containing 1,4-butynediol, a nickel catalyst and about 3 to.- 1-5 of copper, in the form of a water dispersible copper-compound by weight of the nickel catalyst, with.

hydrogen at a pHof no more than about 7, a temperature of about 15' to 100 C. and a pressure of about 0 to 40 atmospheres gauge, the pressure being more than 4 atmospheres gauge at temperatures of to C.

'7'. A process as defined inclaim- 6 wherein the nickel catalyst, is a Raney-type nickel. catalyst.

8'. A. process as defined in claim 6 wherein the copper compound is copper acetate.

References. Cited. in the file of. this patent UNITED STATES PATENTS 2,1573365 Vaughn May 9, 1939 2,319,707 Reppe'et al May 18, 1943 2,335,795" Reppe et al Nov. 30, 1943 2,737,534 Taylor et' a1. Mar. 6, 1956 FOREIGN PATENTS 508,944 Great Britain June 26', 1939 869,053 Germany Mar. 2, 1953 OTHER REFERENCES I Campbell. etal: Chemical Reviews, vol. 3 1, pp. 5.1-. .1942). 

1. A PROCESS FOR THE CATALYTIC HYDROGENATION OF 1,4BUTYNEDIOL TO 1,4-BUTANEDIOL COMPRISING TREATING 1,4BUTYNEDIOL IN LIQUID FORM WITH HYDROGEN AT A PH OF NO MORE THAN ABOUT 7, A TEMPERATURE OF ABOUT 15 TO 100*C. AND A PRESSURE OF ABOUT 0 TO 40 ATMOSPHERES GAUGE IN THE PRESENCE OF A NICKEL CATALYST CARRYING ABOUT 3 TO 15% OF COPPER BY WEIGHT OF THE NICKEL CATALYST, THE PRESSURE BEING MORE THAN 4 ATMOSPHERES GUAGE AT TEMPERATURES OF 60 TO 100*C. 